1. Field of the Invention
The invention relates to a camera module device for recording data that is mounted inside a camera main body and is equipped with a magnetic head for writing or both writing and recording such data as photographing date and time, into and from the magnetic recording area formed on the photographic film inside.
2. Description of the Related Art
Camera module devices for recording data have been known that project such data as photographing date and time onto photographic film at the time of photographing, etc. Such a device can be mounted onto a camera main body, and optically projects the data onto the photographic film in a state in which it is mounted onto the camera main body. In recent years, photographic film on part of which a magnetic recording track has been formed has become known, and camera module devices for data recording that write data into such photographic film have also been suggested.
For example, this kind of module device is disclosed in Japanese Patent Laid Open No. H6-138540, and comprises a communication function for exchanging signals with a control circuit installed in the camera main body and consisting of components such as a microcomputer, a storage means for temporarily storing the received recorded data, and a magnetic head.
During photographing, the data to be written is generated by the camera main body side. During data writing, the data to be written is output from the camera main body side, and at the same time a synchronization signal is output in linkage with the advancing operation of the photographic film, etc. The module device side receives these signals, and then uses a magnetic head to write data such as the photographing date and time supplied and the angle of view information into the magnetic recording track of the corresponding one frame of the photographic film, in linkage with the rewinding operation of the photographic film.
Such a camera module device for data recording has the problems described below.
First, although the device can be freely mounted on or removed from the camera main body, the data to be written by the magnetic head, the synchronization signal for driving the magnetic head, etc. must be generated by and received from the control circuit on the camera main body side. Consequently, it is necessary to embed circuits for implementing such functions in the camera main body side beforehand, thus increasing the cost of manufacturing the camera main body accordingly. Furthermore, the circuits embedded in the camera main body are wasteful to those users who do not need such functions.
Second, conventional camera module devices or camera main bodies are not equipped with a function for verifying the operation of the data writing function of said camera module device. Consequently, whether or not the writing operation was correctly performed can be checked only after the data is actually written and the photographic film is developed, which is inconvenient.
Third, in a camera module device equipped with a magnetic head, the magnetic head is installed in a fixed location. Consequently, if the camera main body side is not equipped with a function for temporarily reverse-feeding the photographic film immediately after photographing, a total of four kinds of module structures must be made available for the camera module device, in order to cope with cameras with different photographic film loading methods and different cartridge loading directions.
Fourth, the data to be recorded in the camera is displayed on the monitoring liquid crystal display panel installed in the camera module device. In the case of an optical camera module, because the volume of data to be projected is not that large, normally all of the projection data is always displayed on the liquid crystal panel at once. In contrast, a large volume of data can be recorded in a magnetic recording track. Consequently, the number of display digits of the liquid crystal panel must be increased in order to display all of the recorded data on the liquid crystal panel at once, which is uneconomical. However, no measures have been taken to address this issue so far.